To prevent your computer from rebooting automatically after a Windows update installs, follow these steps:
Type this in Start menu or CMD:
gpedit.msc
And go to:
Computer Configuration\Administrative Templates\Windows Components\Windows Update
Now double-click "Configure Automatic Updates".
Enable the policy and select the desired operation mode.
Note: The group policy editor only exists in Windows 10 Pro and newer. If you have the Home edition, read the following articles.
Read upon the topic: https://superuser.com/questions/957267/how-to-disable-automatic-reboots-in-windows-10#963933
Additional ways: https://www.windowscentral.com/how-prevent-windows-10-rebooting-after-installing-updates